Russian and Ukrainian security services have foiled a plot to blow up Vladimir Putin shortly after this Sunday's presidential election in Russia, it emerged on Monday.

State television in Russia said that special forces had seized two conspirators in Odessa, southern Ukraine, after an explosion in an apartment in January.

The Chechen alleged ringleader, Adam Osmayev, 31, has reportedly confessed to planning the assassination on the orders of Doku Umarov, the emir of the Islamist insurgency against Moscow's rule in the North Caucasus region.

Channel One showed Osmayev in detentionsaying: "The ultimate aim was to travel to Moscow and try to assassinate Premier Putin." The plan was exposed after the explosion in Odessa on January 4, which was initially thought to be a domestic gas explosion. However, it transpired to be an accident during the preparation of an explosive device.

One of the men, Ruslan Madayev, 26, died in the blast but Ukrainian special forces seized a second, Ilya Pyanzin, 28, two days later. Osmayev, who was shown with blotches of green antiseptic covering wounds on his face, was captured separately later. The men had a laptop with several videos of Mr Putin's cortege travelling through Moscow on it.

Osmayev – who had reportedly been on a federal arrest warrant since 2007 – said they planned to use a tank mine to kill Mr Putin rather than a suicide bomber, although Madayev had been prepared to become a martyr.

Mr Putin did not comment on Monday morning but his spokesman, Dmitry Peskov, confirmed the murder plot was real.

There is likely to be speculation that news of the plot – apparently exposed several weeks ago – was deliberately released by Kremlin-controlled media just before the presidential vote, in order to bolster one of Mr Putin's favourite electoral tactics: suggesting that foreign-backed wreckers are trying to destabilise the motherland.

Channel One made a point of mentioning that Osmayev lived for several years in London, which is also home to Akhmed Zakayev, the Chechen rebel envoy whom Moscow has tried unsuccessfully to extradite.

An FSB (Russian Federal Security Service) operative showed videos of Mr Putin's cortege found on Osmayev's computer. "These were in order to understand where the bodyguards sit and how many cars are escorting, from different angles and streets," he explained.

Madayev and Pyanzin, a Kazakh citizen, were said to have flown to Ukraine from the United Arab Emirates via Turkey "with precise instructions from representatives of Doku Umarov."